TLV493D returns NCK

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Not applicable
Hi,

I'm using a TLV493D with a power separated by FET from microcontroller power, like Slave #1 in figure 14 of I2C interface note (https://www.infineon.com/dgdl/Infineon-TLV493D-A1B6_UM-UM-v01_02-EN.PDF?fileId=5546d462525dbac401530...)

Sometimes my few TLVs return NCK and cannot recover even turn on/off by IO_0 pin.
A difference between the note and my project is SCL pin is high during 200us of after power on by getting IO_0 high.

Does this SCL behavior seriously affect the I2C address setting/communication?

I'm feeling strange since many of my TLVs are successfully work but this happens with few chips beside low frequency.
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1 Solution
WoS
Employee
Employee
First solution authored
The sequence "Start - 0x00 - Stop" (which is basically sending just the general call address 0 on the i2c bus) resets the sensor at the end of the frame.

Is SDA on low on intention during start-up? The sensor captures the SDA level on power-up and reset (on TLV493D-A1B6) to change its address, this you can find in chapter 6 on the document you mentions...

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5 Replies
User13282
Level 3
Level 3
25 replies posted 10 replies posted 5 replies posted
Could you please provide some more details? Sketch from: 1. of your circuitry incl. resistors/capacitors values on I2C bus. 2. Screenshot of the timing of I2C bus during configuration phase. Thanks.
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Not applicable
Thank you for your reply!

Here is the schematics:

3021.attach

The timing of I2C bus:
3022.attach

Also, I tried getting SCL low during the configuration phase, however, some chips still return NCK sometimes.
3023.attach

Sincerely
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User13282
Level 3
Level 3
25 replies posted 10 replies posted 5 replies posted
Looks good. But, you should give it a try: Remove R22 and assemble R4 instead.
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Not applicable
Hmm...

We have already produced over a thousand units with this circuit and difficult to change parts of them from now.
I want to try to improve it without any changes to schematics.

I found "General Reset" command that sends 0x00 to SDA but Is this effective for all time in irrespective of internal state?
I mean, Is there any non-volatile area or register and no possibility to inhibit resetting?
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WoS
Employee
Employee
First solution authored
The sequence "Start - 0x00 - Stop" (which is basically sending just the general call address 0 on the i2c bus) resets the sensor at the end of the frame.

Is SDA on low on intention during start-up? The sensor captures the SDA level on power-up and reset (on TLV493D-A1B6) to change its address, this you can find in chapter 6 on the document you mentions...
0 Likes